Developing electrolyte formulations with zwitterionic monomers for better lithium-ion batteries

Lithium-ion battery (LiB) performance is dependent on: how fast lithium ions can move between the electrodes through the electrolyte; and the chemical stability of the electrodes to store the lithium ions. If the properties of the electrolyte are suboptimal, then the batteries cannot store energy effectively, have a limited lifetime, and take a long time to charge. For an electric vehicle (EV), this means reduced range, regular battery replacement and long wait times for users upon “refuelling”. Thus, the electrolyte and its interaction with the electrodes are critical to LiB deployment. Current LiBs are nearing their theoretical performance limits. Moreover, they employ expensive raw materials, such as cobalt, that compromise their green profile and limit the cost reduction needed for their widespread uptake.

In the BetterLiBs project, the project partners will use novel polymerizable zwitterion monomers (ZIMONS) to improve LiB performance. ZIMONS have equal numbers of positive- and negatively-charged functional groups, have high thermal stability and are polymerizable to protect the electrode surfaces. With these properties, we expect they will reduce the cost of LiBs by up to 33%, increase maximum number of cycles to 2,500, increase energy density up to 700 Wh/kg and decrease charging time to 30mins for EV-type 80 Wh battery.